Accompanying increasing demands for saving energy in recent years, there is a growing need for a toner capable of fixing at lower temperatures. The use of a polyester resin having a low softening temperature has been proposed as means of lowering fixation temperature. However, the use of an ordinary amorphous polyester resin having a low softening temperature results in the occurrence of blocking due to melt adhesion of toner particles during storage or transport.
Therefore, a technology has been proposed that uses a crystalline polyester resin having a sharp melt property such that viscosity significantly decreases when the melting point is exceeded as means for realizing both blocking resistance and low-temperature fixability (Patent Literatures 1 to 3).